This invention relates to a breast pump which can perform the automatic suction with the following advantages: 1) a breast-milking mother can stop the operation of breast pump immediately, when her breast site feels painful through continual suction, 2) the suction can be immediately made available by re-pushing a switch, thus more convenient to use, 3) since the breast pump has a massage function in addition to the basic suction of human milk, thus removing a breast stiffness in an efficient manner and improve the overall functions of the breast pump, 4) the rapid detachment of the breast pump after use can be accomplished through a suction release value, thus making the separation procedure of breast pump easier, 5) since the induction neck of breast pump is equipped with a separate induction conduit which is extended to the inside of a breast milk bottle, human milk can be directly dropped to the bottle, whereby disinfecting the bottle is unnecessary, and 6) since the breast milk bottle is connected to the main body of the breast pump with a transparent hose, the attachment of the breast pump to the mother's nipple and breast can be easily seen.